Viridian's Ward

For the duration, you gain a bonus to your AC equal to your spellcasting ability modifier, and you gain advantage on saving throws against spells.

At Higher Levels. If you cast Viridian's Ward using a 5th level spell slot, it lasts up to 10 minutes. If you cast Viridian's Ward with a 7th level spell slot, it lasts up to an hour. If you cast Viridian's Ward with a 9th level spell slot, it lasts 24 hours, and does not require concentration.